In the oxygen injection process of "CO2 + O2" in-situ leaching uranium, oxygen is prone to bubble coalescence and flow regime deterioration during long distance transportation, which in turn induces gas blockage, resulting in intermittent liquid injection, and decrease in leaching efficiency. To reveal the mechanism by which bubble size evolution regulates flow stability, this study designed a visualization experimental system for static mixers used in in-situ leaching uranium. Particle shadow velocimetry (PSV) was employed in combination with multi-stage image processing techniques—including Gaussian filtering, adaptive threshold segmentation, and morphological reconstruction. To achieve high resolution in-situ observation of micro bubble size, distribution and dynamic behavior. The results show that as oxygen concentration increase from 15 mg/L to 700 mg/L, microbubble diameter (d50) rise from 528 μm to 823 μm. Conversely, increasing water flow rate from 0.5 m3/h to 2.0 m3/h, microbubble diameter (d 50) reduce from 945 μm to 412 μm, indicating significantly enhance dispersion capability. With rising oxygen concentration, the flow patterns evolve sequentially from fog flow, through bubble flow and transition flow, to slug flow. In the slug flow pattern, the big bubbles periodically collapse, leading to frequent gas blockage issues on-site. This study demonstrates that the proposed image processing method provides highly reliable data for microbubble size distribution, coalescence frequency, and flow pattern identification, offering a solid foundation for process optimization and control of oxygen injection in in-situ leaching uranium.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |